Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Status
The first post of this thread is a WikiPost and can be edited by anyone with the appropiate permissions. Your edits will be public.
I also own a OWC Thunderbolt Hub (TB4HUB5P). The USB speed of the JMS583 and 9210B-CG on the USB-A Port (10 gbps) were pretty much the same as connected directly to the Thunderbolt port.
That is a Thunderbolt 4 device. I specifically said to try a Thunderbolt 3 device for a reason.

A Thunderbolt 4 device will use USB tunnelling when connected to a Thunderbolt/USB4 host. USB tunnelling uses the USB controller of the host instead of the USB controller of the Thunderbolt device. The host in this case is the M1 Mac and the USB controller of the M1 Mac is slower than other USB controllers.

A Thunderbolt 3 device does not have USB tunnelling.

You can disable USB tunnelling on a Thunderbolt 4 device by having the Thunderbolt 4 device downstream from a Thunderbolt 3 device.
 
The acasis enclosure uses a JMS583 USB to NVMe bridge and will not work because of power limitations of the USB-C Hubs like the HyperDrive 6-in-1 (HD319B). I also tested a bunch of other USB-C Hubs (Satechi, Ugreen, Mokin). They all don't provide enough power on the Thunderbolt Port to use a thunderbolt enclosure (I also tested the OWC Envoy Express). The HyperDrive is the only USB-C hub which also allows to charge the macbook with the second USB-C Port (5 gbps) albeit with lower wattage and provides 4k 60hz on a HDMI port. Just leaving this here for people which are in a similar situation.

So basically you're saying it's not the fault of the Acasis enclosure. You're right. The Acasis (and the JMS) enclosure itself works fine.

Pro-tip:
Caldigit TS3 Plus

JMS2.png
 
So basically you're saying it's not the fault of the Acasis enclosure. You're right. The Acasis (and the JMS) enclosure itself works fine.

Not exactly because I also noticed that the Acasis enclosure from time to time only powers on after unplugging and replugging the Thunderbolt cable. I only tested with two Thunderbolt enclosures (Acasis and OWC Envoy Express). Since I don't own a Sabrent Rocket XTRM or a Samsung X5 enclosure I can't say for sure if all Thunderbolt enclosures are prone to this behaviour.

You can disable USB tunnelling on a Thunderbolt 4 device by having the Thunderbolt 4 device downstream from a Thunderbolt 3 device.

Sadly I don't own a Thunderbolt 3 dock with a native 10 gbps controller. So I can't check but thanks for the heads-up.
 
Sadly I don't own a Thunderbolt 3 dock with a native 10 gbps controller. So I can't check but thanks for the heads-up.
The Thunderbolt controller in a Thunderbolt 3 dock includes a 10 Gbps controller that can be used with the downstream Thunderbolt port. Are you saying you don't have any Thunderbolt 3 devices that have two Thunderbolt 3 ports (one for upstream and one for downstream)?

The third party 10 Gbps controllers used in most Alpine Ridge based Thunderbolt 3 docks (not connected to the downstream Thunderbolt port) are usually the inferior ASMedia ASM1142 which is limited to 8 Gbps.

Titan Ridge (Thunderbolt 3) and Goshen Ridge (Thunderbolt 4) docks/hubs usually don't add any USB controllers. Instead, they use a 10 Gbps hub connected to the USB controller of the Thunderbolt controller. In the case of Goshen Ridge connected to a USB4 host such as an M1 Mac, the USB controller of the Goshen Ridge Thunderbolt controller is bypassed - the hub is controlled by the USB controller of the M1 Mac.
 
Not exactly because I also noticed that the Acasis enclosure from time to time only powers on after unplugging and replugging the Thunderbolt cable. I only tested with two Thunderbolt enclosures (Acasis and OWC Envoy Express). Since I don't own a Sabrent Rocket XTRM or a Samsung X5 enclosure I can't say for sure if all Thunderbolt enclosures are prone to this behaviour.



Sadly I don't own a Thunderbolt 3 dock with a native 10 gbps controller. So I can't check but thanks for the heads-up.

You tested Acasis JMS (with a TB3 cable) and Acasis TB3 then, right?

Same setup here with the exception that I use a Caldigit TS3+ with an eGPU. Also I got both SSD enclosures (USB + TB3) connected to the dock.

Only the Acasis JMS shows that symptom on the 10GB port of the hub *sometimes* (every 5 month or so).

Be sure to have good cables. I had a couple of bad (even pricey) ones. Caldigit 1m TB3 cable failed me with random disconnects. Cablematters were fine. Or use TB4 cables instead.

I can live with the inferior 8Ggbs (didn't notice that, thanks @joevt) and the slightly reduced Acasis TB3 SSD trougput (compared to the direct connection) in trade for a rock solid system and one cable to plug in for the whole setup. That's as close as the whole TB3 idea was meant in the first place.

@joevt

Nice explanation. Source would be nice for further readings...
 
One of the big issues with these smaller enclosures in general is the drive gets so hot that it thermal throttles.

1. Do we know of any Thunderbolt 3 NVME enclosures that are able to keep the drive cooler via a fan, heatsink or
some other cooling method within the enclosure?

2. Do we know of any enclosures that are able to fit a NVME drive with a heatsink (3rd party heatsink or the drive's own brand heatsink)?
 
One of the big issues with these smaller enclosures in general is the drive gets so hot that it thermal throttles.

1. Do we know of any Thunderbolt 3 NVME enclosures that are able to keep the drive cooler via a fan, heatsink or
some other cooling method within the enclosure?


2. Do we know of any enclosures that are able to fit a NVME drive with a heatsink (3rd party heatsink or the drive's own brand heatsink)?

Acasis NVMe TB3 enclosure does that passivly cooled. Gets warm/hot (as the aluminium fins should to get the heat away) but does not throttle. Fans are gimmicks.
 
I see. Do share your results from both Amorphous Diskmark and Blackmagic post project completion. Below is an interesting review on different chipsets with different environments, but all performed on windows.

OS Extended, APFS, APFS encrypted all gave me similar results - encrypted was a little better, this is with the Acasis enclosure.

Haven't had a chance to try it on an M1.
 

Attachments

  • APFS_Encrypted_BM.png
    APFS_Encrypted_BM.png
    870.5 KB · Views: 165
  • APFS_BM.png
    APFS_BM.png
    835.6 KB · Views: 158
  • OX_Extended_BM.png
    OX_Extended_BM.png
    1.1 MB · Views: 178
  • OX_Extended.png
    OX_Extended.png
    513.9 KB · Views: 167
  • APFS_Encrypted.png
    APFS_Encrypted.png
    582.2 KB · Views: 188
  • APFS.png
    APFS.png
    548.1 KB · Views: 178
OS Extended, APFS, APFS encrypted all gave me similar results - encrypted was a little better, this is with the Acasis enclosure.

Haven't had a chance to try it on an M1.
Looks pretty similar to my results with 2TB SN750. Your 4KQD1 write results on the other hand ?, I haven't seen anything like it on macOS
 
Hi everyone..

I'm new to this site as I've been having the biggest headache trying to get my external ssd to work with my MBP M1

I got the Acasis USB4/Thunderbolt 3 m.2 case, which I realise is not the best choice seeing how mac handle usb.

I'm using the case with a Sabrent gen4 rocket 4 plus 2TB stick. (Possibly overkill)

It worked first time I inserted it and let me format the drive etc, but then refuses to acknowledge that it's connected. The light is on the Acasis but sys information has 0 devices showing as connected, nothing in disk utility.

I purchased another identicle enclosure and memory and same thing happened, after formatting, the drive won't be seen.

Anything I can do please, or has someone experienced the same thing?


Edit: I just refreshed the list in system info and have this showing now.
 

Attachments

  • 20211026_173309.jpg
    20211026_173309.jpg
    736.5 KB · Views: 156
  • 20211026_173536.jpg
    20211026_173536.jpg
    555.7 KB · Views: 158
Last edited:
Hi everyone..

I'm new to this site as I've been having the biggest headache trying to get my external ssd to work with my MBP M1

I got the Acasis USB4/Thunderbolt 3 m.2 case, which I realise is not the best choice seeing how mac handle usb.

I'm using the case with a Sabrent gen4 rocket 4 plus 2TB stick. (Possibly overkill)

It worked first time I inserted it and let me format the drive etc, but then refuses to acknowledge that it's connected. The light is on the Acasis but sys information has 0 devices showing as connected, nothing in disk utility.

I purchased another identicle enclosure and memory and same thing happened, after formatting, the drive won't be seen.

Anything I can do please, or has someone experienced the same thing?


Edit: I just refreshed the list in system info and have this showing now.
You didn't show the PCI tab of System Information.app. If the NVMe is detected then it should be listed there.

Maybe you need to reseat the Sabrent in the enclosure? Unlikely since you tried two enclosures / Sabrents already.

Maybe the ACASIS enclosure doesn't like the Sabrent? Maybe too much power required? Do you have another NVMe to test?

Maybe the ACASIS doesn't like the M1 Mac's Thunderbolt 4 port. Do you have a Thunderbolt 3 or Thunderbolt 4 dock to connect it to?

The Acasis USB4/Thunderbolt enclosure is not really USB4. It's actually Thunderbolt 3 or USB 3.1 Gen 2 depending on what you connect it to. It would not be able to connect at USB4 speed to a USB4 host that does not support Thunderbolt (but I don't know of any USB4 hosts that don't also support Thunderbolt).
 
You didn't show the PCI tab of System Information.app. If the NVMe is detected then it should be listed there.

Maybe you need to reseat the Sabrent in the enclosure? Unlikely since you tried two enclosures / Sabrents already.

Maybe the ACASIS enclosure doesn't like the Sabrent? Maybe too much power required? Do you have another NVMe to test?

Maybe the ACASIS doesn't like the M1 Mac's Thunderbolt 4 port. Do you have a Thunderbolt 3 or Thunderbolt 4 dock to connect it to?

The Acasis USB4/Thunderbolt enclosure is not really USB4. It's actually Thunderbolt 3 or USB 3.1 Gen 2 depending on what you connect it to. It would not be able to connect at USB4 speed to a USB4 host that does not support Thunderbolt (but I don't know of any USB4 hosts that don't also support Thunderbolt).

Thanks for your reply.. I've added a image of the Pci information.

It's probably the enclosure, I've ordered a genuine apple TB3 cable to rule that out.

Really weird as both enclosures plus new ssd did the same, formatted and mounted fine then stopped second time I tried plugging in after eject.

Sabrent are saying to format it in Exfat as there are known issues with APFS but still doesn't explain why the Disk utility can't see it, plus I can't reformat as I can't see the drive ?
 

Attachments

  • 20211027_172140.jpg
    20211027_172140.jpg
    270.2 KB · Views: 163
Thanks for your reply.. I've added a image of the Pci information.
PCI info shows the USB controller of the Titan Ridge in the ACASIS enclosure. But the NVMe isn't there.

It's probably the enclosure, I've ordered a genuine apple TB3 cable to rule that out.
How would a different cable rule out the enclosure? What cable are you using now? For Thunderbolt speeds it needs to be a Thunderbolt 3 cable. Your earlier screenshots showed a proper 40 Gbps x1 link with link width correctly at x2.

Really weird as both enclosures plus new ssd did the same, formatted and mounted fine then stopped second time I tried plugging in after eject.
One would expect that the same enclosure plus the same NVMe plus the same procedure would yield the same result. So that's not weird. I think you mean what's weird is the result.

Sabrent are saying to format it in Exfat as there are known issues with APFS but still doesn't explain why the Disk utility can't see it, plus I can't reformat as I can't see the drive
I think the issue is with the ACASIS enclosure. It doesn't like the Sabrent NVMe after its formatted. You'll need to change one of those.
But before that, you could try their suggestion of formatting it in ExFAT. You'll need a different enclosure to do that though. Or maybe you can try connecting it to USB instead of Thunderbolt. It might be visible using USB so you can reformat it while connected as USB and see if that fixes the issue with connecting as Thunderbolt.
 
PCI info shows the USB controller of the Titan Ridge in the ACASIS enclosure. But the NVMe isn't there.


How would a different cable rule out the enclosure? What cable are you using now? For Thunderbolt speeds it needs to be a Thunderbolt 3 cable. Your earlier screenshots showed a proper 40 Gbps x1 link with link width correctly at x2.


One would expect that the same enclosure plus the same NVMe plus the same procedure would yield the same result. So that's not weird. I think you mean what's weird is the result.


I think the issue is with the ACASIS enclosure. It doesn't like the Sabrent NVMe after its formatted. You'll need to change one of those.
But before that, you could try their suggestion of formatting it in ExFAT. You'll need a different enclosure to do that though. Or maybe you can try connecting it to USB instead of Thunderbolt. It might be visible using USB so you can reformat it while connected as USB and see if that fixes the issue with connecting as Thunderbolt.
Really appreciate your response ??

I was using the cable that came with it which is a TB3. Your right the cable probably isn't the issue and as you correctly point out the case is being recognised by the mac so makes sense some kind of issue with the case and comm with the nvme.

I just need to figure out how to format to Exfat now, as I do not have another PC or enclosure
 
I just need to figure out how to format to Exfat now, as I do not have another PC or enclosure
Try my suggestion of connecting it to a non-Thunderbolt USB type A port? You'll need a type A to type C cable.
 
One of the big issues with these smaller enclosures in general is the drive gets so hot that it thermal throttles.

1. Do we know of any Thunderbolt 3 NVME enclosures that are able to keep the drive cooler via a fan, heatsink or
some other cooling method within the enclosure?

2. Do we know of any enclosures that are able to fit a NVME drive with a heatsink (3rd party heatsink or the drive's own brand heatsink)?
I've got 4 NVMe drives in an OWC Express 4m2 and they're all happy as can be under that fan. I have a single-drive Sabrent TB3 enclosure that, no ********, could scald someone if you held it against bare skin. That's the same enclsoure where they notched the g-ddamned TB3 port so you can ONLY USE THEIR SHORT CABLE ?

I just smartctl walked them all and none of them are reading above 50 Celsius but they aren't under load right now. I have the four NVMe devices in a ZFS pool of two mirrored vdevs and just through sustained writes and reads at it and the highest temp i registered was one of the Samsung 970 EVOs hit 62 Celsius but one of the ADATA drives may have something going on with it, not sure how to interpret this yet:


=== START OF INFORMATION SECTION === Model Number: ADATA SX8200PNP Serial Number: 2K482L1DEC1G Firmware Version: 42AZS6AC PCI Vendor/Subsystem ID: 0x1cc1 IEEE OUI Identifier: 0x000000 Controller ID: 1 NVMe Version: 1.3 Number of Namespaces: 1 Local Time is: Thu Oct 28 16:49:06 2021 CDT Firmware Updates (0x14): 2 Slots, no Reset required Optional Admin Commands (0x0017): Security Format Frmw_DL Self_Test Optional NVM Commands (0x005f): Comp Wr_Unc DS_Mngmt Wr_Zero Sav/Sel_Feat Timestmp Log Page Attributes (0x0b): S/H_per_NS Cmd_Eff_Lg Telmtry_Lg Maximum Data Transfer Size: 64 Pages Warning Comp. Temp. Threshold: 75 Celsius Critical Comp. Temp. Threshold: 80 Celsius Supported Power States St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat 0 + 9.00W - - 0 0 0 0 0 0 1 + 4.60W - - 1 1 1 1 0 0 2 + 3.80W - - 2 2 2 2 0 0 3 - 0.0450W - - 3 3 3 3 2000 2000 4 - 0.0040W - - 4 4 4 4 15000 15000 === START OF SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED SMART/Health Information (NVMe Log 0x02) Critical Warning: 0x00 Temperature: 42 Celsius Available Spare: 100% Available Spare Threshold: 10% Percentage Used: 9% Data Units Read: 231,384,858 [118 TB] Data Units Written: 109,661,198 [56.1 TB] Host Read Commands: 15,271,538,436 Host Write Commands: 2,916,416,665 Controller Busy Time: 114,457 Power Cycles: 668 Power On Hours: 5,057 Unsafe Shutdowns: 37 Media and Data Integrity Errors: 0 Error Information Log Entries: 0 Warning Comp. Temperature Time: 0 Critical Comp. Temperature Time: 0 Thermal Temp. 1 Transition Count: 73 Thermal Temp. 1 Total Time: 278 Error Information (NVMe Log 0x01, 16 of 256 entries) No Errors Logged


There isn't enough clearance for heat sinks on-drive inside the Express 4M2 AFAIK. i have a few I bought when I had to buy some monstrosity of a drive for a PS5 and I don't think I could stick anything on them and not interfere with the fan path gimmick or not.
 
Last edited:
Recently bought a specced out 4 tb M1 Pro Max

What do you guys think about this external SSD combination?

Basically the Acadia USB “4.0” and Firecuda 530

ACASIS NVMe Enclosure Type-C USB 4.0 External M.2 PCIe SSD Enclosure Reader SSD NVMe Dock Station Tool-Free Portable External Enclosure 40GBps


+

Seagate FireCuda 530 1TB Solid State Drive - M.2 PCIe Gen4 ×4 NVMe 1.4, speeds up to 7300 MB/s, Compatible PS5 Internal SSD, 3D TLC NAND, 1275 TBW, 1.8M MTBF, 3yr Rescue Services (ZP1000GM30013)


I’m also a bit confused on why the Acasis is not truly USB 4.0 or even 3.2 gen 2 but is 3.1 gen 2.

If that’s true that’s ****** that they advertise it as USB 4.0.

Where are all the true USB 4.0 enclosures? Are they in the process of being made sometime this year?

Even if they are made, does the new M1 pro max usb 4 ports even allow for the full throughput to be achieved?
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
Recently bought a specced out 4 tb M1 Pro Max

What do you guys think about this external SSD combination?

Basically the Acadia USB “4.0” and Firecuda 530

ACASIS NVMe Enclosure Type-C USB 4.0 External M.2 PCIe SSD Enclosure Reader SSD NVMe Dock Station Tool-Free Portable External Enclosure 40GBps


+

Seagate FireCuda 530 1TB Solid State Drive - M.2 PCIe Gen4 ×4 NVMe 1.4, speeds up to 7300 MB/s, Compatible PS5 Internal SSD, 3D TLC NAND, 1275 TBW, 1.8M MTBF, 3yr Rescue Services (ZP1000GM30013)


I’m also a bit confused on why the Acasis is not truly USB 4.0 or even 3.2 gen 2 but is 3.1 gen 2.

If that’s true that’s ****** that they advertise it as USB 4.0.

Where are all the true USB 4.0 enclosures? Are they in the process of being made sometime this year?

Even if they are made, does the new M1 pro max usb 4 ports even allow for the full throughput to be achieved?
If you read this thread then you might think about getting a different enclosure.

When describing USB speeds, I usually use the earliest spec that includes the speed because it's the simplest.
5 Gbps = USB 3.0 = USB 3.1 gen 1 = USB 3.2 gen 1x1
10 Gbps = USB 3.1 gen 2 = USB 3.2 gen 2x1
20 Gbps = USB 3.2 gen 2x2

USB 3.2 gen 2 could mean gen 2x1 or gen 2x2 but there's no gen 2x2 with USB 3.1 so I just say USB 3.1 gen 2.

The Acasis has a Thunderbolt controller and a USB adapter. If you connect to a host that supports Thunderbolt then you can get ≈22 Gbps (uses PCIe tunnelling over Thunderbolt to communicate directly with the NVMe). Otherwise you are limited to 10 Gbps (uses a USB 3.1 gen 2 to NVMe bridge).

A USB4 host might not have support for Thunderbolt. If you connect the Acasis to such a USB4 host, then it will be limited to 10 Gbps speed even if the USB4 host supports PCIe tunnelling. I don't know of any such USB4 hosts; all the USB4 hosts I know about also support Thunderbolt.

Thunderbolt is 41.25 Gbps on the wire (uses 64b/66b encoding -> 40 Gbps of data) while USB4 is 40 Gbps on the wire (uses 128b/132b encoding -> 38.8 Gbps of data). There's some other differences.

https://en.wikipedia.org/wiki/USB
https://en.wikipedia.org/wiki/USB4
https://en.wikipedia.org/wiki/Thunderbolt_(interface)

Intel makes discrete Thunderbolt 4 controllers that also support USB4. They also make CPUs with integrated Thunderbolt (Ice Lake) and Thunderbolt 4 (Tiger Lake).

Apple has integrated Thunderbolt4/USB4 controllers in their M1 Macs.

AMD will make their own USB4 controllers for their Epyc CPUs? I don't know much about that. Will it support Thunderbolt and/or PCIe tunnelling?

VIA Labs will make USB4 hub chips that don't support Thunderbolt or PCIe tunnelling. I don't know much about this either.
https://www.via-labs.com/product_show.php?id=114
It's a hub so it should be able to pass PCIe tunnelling to downstream devices. USB4 hubs are supposed to be able to handle downstream Thunderbolt devices so the Acasis should be able to connect to a USB4 host that doesn't support Thunderbolt by being connected to a USB4 hub (I could be wrong about that).
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
  • Like
Reactions: Amethyst1
The Thunderbolt controller in a Thunderbolt 3 dock includes a 10 Gbps controller that can be used with the downstream Thunderbolt port. Are you saying you don't have any Thunderbolt 3 devices that have two Thunderbolt 3 ports (one for upstream and one for downstream)?

The third party 10 Gbps controllers used in most Alpine Ridge based Thunderbolt 3 docks (not connected to the downstream Thunderbolt port) are usually the inferior ASMedia ASM1142 which is limited to 8 Gbps.

Titan Ridge (Thunderbolt 3) and Goshen Ridge (Thunderbolt 4) docks/hubs usually don't add any USB controllers. Instead, they use a 10 Gbps hub connected to the USB controller of the Thunderbolt controller. In the case of Goshen Ridge connected to a USB4 host such as an M1 Mac, the USB controller of the Goshen Ridge Thunderbolt controller is bypassed - the hub is controlled by the USB controller of the M1 Mac.
Thank you for the reply. I did my best to try to read it and understand it, but some of the information is still a bit over my head.

I’ve read a few pages back now, and the only enclosure people seem to mention that works well with a WD 750 is the Acasis.

I know there’s a Orico, but that it can be buggy. There’s the Thunder one with the small fan, but I’ve heard that fans are gimmicks.

Ideally I’d want an enclosure with a goshen ridge chip, but bizarrely there are none yet (aside from in hubs and the Gigadrive) even when you’d think it’s an easy chip to mass produce with an enclosure in china.

Is there a specific enclosure you’d recommend that is better than the Acasis “UBS 4.0”?
 
Ideally I’d want an enclosure with a goshen ridge chip, but bizarrely there are none yet (aside from in hubs and the Gigadrive) even when you’d think it’s an easy chip to mass produce with an enclosure in china.
Goshen Ridge is not good for PCIe devices (GPU, NVMe) since it only has one PCIe lane which would limit bandwidth to ≈750 MB/s instead of the usual 2800 MB/s.
I don't think you can use Maple Ridge for a Thunderbolt peripheral?

Is there a specific enclosure you’d recommend that is better than the Acasis “UBS 4.0”?
I don't know. They're all mostly the same to me. The Acasis is nice because it gives max performance for both USB and Thunderbolt hosts when it works properly.

One that I tried was https://www.amazon.ca/Thunderbolt-Enclosure-Thunderbolt3-NVME-Drive/dp/B07N67P39W
but mostly I used it for an eGPU.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
Hmmm interesting.

Thank you for the education.

For the Gigadrive that is now delayed, since it uses Goshen ridge, and has only 1 Pcie lane, you’re saying that the 2800 MBP/s is channeled only through that 1 lane? (Confused because you’re saying that it would be limited to 750 mb/s)


Final dumb question, but if TB3 supports 4 lanes of PCIE, and the theoretical maximum for data transfer is 40 gb/s for any Pcie gen 4 SSDs like the firecuda 530, what exactly is limiting the data transfer to 2800 MB/s?

Why aren’t we achieving speeds like 5 or even 10 mb/s? What type of controller needs to be made to reach those speeds in the future?
 
For the Gigadrive that is now delayed, since it uses Goshen ridge, and has only 1 Pcie lane, you’re saying that the 2800 MBP/s is channeled only through that 1 lane? (Confused because you’re saying that it would be limited to 750 mb/s)

Probably it's a scam. I suppose it could have other chips but that would be a waste.

Final dumb question, but if TB3 supports 4 lanes of PCIE, and the theoretical maximum for data transfer is 40 gb/s for any Pcie gen 4 SSDs like the firecuda 530, what exactly is limiting the data transfer to 2800 MB/s?

Why aren’t we achieving speeds like 5 or even 10 mb/s? What type of controller needs to be made to reach those speeds in the future?
Thunderbolt 3 can do ≈40 Gbps (5000 MB/s). I've never seen anything get better than ≈3000 MB/s.
The Apple Pro Display XDR can use up to 38.9 Gbps but that's for display data which has priority. Any bandwidth not used for displays can be used by data up to ≈3000 MB/s. I'm not sure why there's a limit for data. There is some Thunderbolt overhead but 40% for that seems extreme so something else is happening. The USB4 spec describes a tradeoff between latency and performance.

The maximum you could expect from 4 lanes of PCIe gen 3 (which is what Thunderbolt controllers use) is ≈3500 MB/s (see any benchmarks for the fastest gen 3 NVMe drives) so the Thunderbolt speed is not too far off.

One thing I haven't seen benchmarked is multiple Thunderbolt NVMe devices connected to the same Thunderbolt port of an integrated Thunderbolt controller (Ice Lake, Tiger Lake, Apple Silicon) since integrated Thunderbolt controllers don't use real PCIe (they are inside a CPU so it doesn't need to be limited by PCIe) they won't necessarily be limited to 3500 MB/s. So in this setup while the max of each Thunderbolt NVMe device will be ≈2800 MB/s, they might have a higher total up to 40 Gbps.

I have tested multiple Thunderbolt NVMe devices connected to two ports of a discrete Thunderbolt controller (Titan Ridge) but I didn't get much higher than ≈23 Gbps so repeating the test with both devices connected to the same port would probably not be any better.
 
Probably it's a scam. I suppose it could have other chips but that would be a waste.


Thunderbolt 3 can do ≈40 Gbps (5000 MB/s). I've never seen anything get better than ≈3000 MB/s.
The Apple Pro Display XDR can use up to 38.9 Gbps but that's for display data which has priority. Any bandwidth not used for displays can be used by data up to ≈3000 MB/s. I'm not sure why there's a limit for data. There is some Thunderbolt overhead but 40% for that seems extreme so something else is happening. The USB4 spec describes a tradeoff between latency and performance.

The maximum you could expect from 4 lanes of PCIe gen 3 (which is what Thunderbolt controllers use) is ≈3500 MB/s (see any benchmarks for the fastest gen 3 NVMe drives) so the Thunderbolt speed is not too far off.

One thing I haven't seen benchmarked is multiple Thunderbolt NVMe devices connected to the same Thunderbolt port of an integrated Thunderbolt controller (Ice Lake, Tiger Lake, Apple Silicon) since integrated Thunderbolt controllers don't use real PCIe (they are inside a CPU so it doesn't need to be limited by PCIe) they won't necessarily be limited to 3500 MB/s. So in this setup while the max of each Thunderbolt NVMe device will be ≈2800 MB/s, they might have a higher total up to 40 Gbps.

I have tested multiple Thunderbolt NVMe devices connected to two ports of a discrete Thunderbolt controller (Titan Ridge) but I didn't get much higher than ≈23 Gbps so repeating the test with both devices connected to the same port would probably not be any better.
Thank you for your detailed and knowledgeable reply.
 
This has an older revision of the TB3 PCB. You can see it on the multiple LED's. An it gets burning hot.

@M1promax

If you can live with TB3 only I'd still recommend the Acasis TB3 (not the USB4) for speed and for the passive cooling support on the chassis.

I also tried multiple enclosures. The combination of the SSD with the enclosure can be tricky.

There's no reason to pay a higher price for a PCI Gen4x4 if you plan to use it only in an enclosure as the speed is limited anyway. Even if you plan to use the SSD later (futureproof buy). In my experience by the time coming there's alway a new champion around...

For price get a Acasis TB3 + WD 750. If SSD data safety and absolutely sustained performance (depends on your scenario) is important get an Acasis TB3 + Samsung 970Pro (my setup). Both should be reliable every day solutions.

You pay a slightly higher price for peace of mind. I think that's why you bought the Mac in the first place anyway?

For real life, you know :)?
 
Last edited:
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
This has an older revision of the TB3 PCB. You can see it on the multiple LED's. An it gets burning hot.

@M1promax

If you can live with TB3 only I'd still recommend the Acasis TB3 (not the USB4) for speed and for the passive cooling support on the chassis.

I also tried multiple enclosures. The combination of the SSD with the enclosure can be tricky.

There's no reason to pay a higher price for a PCI Gen4x4 if you plan to use it only in an enclosure as the speed is limited anyway. Even if you plan to use the SSD later (futureproof buy). In my experience by the time coming there's alway a new champion around...

For price get a Acasis TB3 + WD 750. If SSD data safety and absolutely sustained performance (depends on your scenario) is important get an Acasis TB3 + Samsung 970Pro (my setup). Both should be reliable every day solutions.

You pay a slightly higher price for peace of mind. I think that's why you bought the Mac in the first place anyway?

For real life, you know :)?
Perfect response! Makes sense. Thank you.

Weirdly the price for the WD750 4tb and firecuda are the same.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.